The BBFC introduced the film certification system in 1912 to rate films for safety and protect audiences. Over time, the ratings were expanded and modified to classify films by age groups. Key changes included adding ratings for children 16 and over in 1932, raising the X rating to 18 in 1970, introducing PG in 1982, and adding the 12 rating in 1989 to provide a category between PG and 15. The ratings system continues to evolve to this day.